How long and at what temperature did you cook the quiche? If you cook it too fast, the top could overcook before the middle is set ... and you have to deal with more carry-over. You're generally best cooking it low and slow, like a cheesecake. If you want it browned, you can always put it under the broiler for a few seconds.
–
JoeMar 25 '13 at 14:03

Those fresh eggs hold firmer as well. See SAJ14SAJ's answer and go gently with the whisk when making any custard.
–
MandoMandoMar 25 '13 at 15:08

You could let the custard mixture rest in the refrigerator for a while to let bubbles escape, much as one does with crepe batter.
–
PointyMar 25 '13 at 21:24

As SAJ14SAJ says, a quiche is basically a custard. The eggs in a custard work the same way no matter if you are making a quiche, a creme caramel, or a creme patisserie. They have lots of different proteins, which float free in the liquid part of the egg while the eggs are raw.

When you start heating the egg mixture, the proteins start to bind together, forming a three dimensional mesh. The more you heat it, the more dense the mesh becomes, because some of the proteins which did not form cross-connections at, say, 60 degrees Celsius, start forming them at 70. In the beginning, this means that your egg mixture goes from liquid to a dense liquid to a soft amorphous solid. Then, with more connections formed, the solid mesh grows stronger. The new cross-links also reduce the volume of the holes of your mesh.

At some point, you get the result you describe. The mesh is very strong, so that you perceive it as rubbery when you bite on it. It has also contracted considerably, expelling the more liquid/watery parts of the egg, while the proteins stay in the mesh and the fats cling to it. This expelled liquid also started cooking, creating bubbles large enough to see. This is where your "aero" description comes from. Depending on how you treat your quiche before cutting, and also whether there are ingredients present which can soak up this watery liquid, you can see the water flowing out of the bubbles after cutting it, forming a puddle on the bottom of the plate, or it may have disappeared (soaked up, flowed out, evaporated) before cutting.

The solution is to treat the quiche the same way you treat any other custard. Bake it on a low temperature, and take it out as early as possible. The best way to know for sure is to stick a thermometer into the middle and to remove it at around 85 degrees Celsius, but as quiches tend to give you some more leeway than other custards, you can also try learning to rely on a combination of cooking time and intuition, which works as long as you use the same oven and the same quiche pan. (The correct time will vary with differences in oven calibration, pan material and pan geometry). Covering the top with foil might be a good idea if you are afraid that the top layer gets heated too quickly, just remember to uncover it at the end for a golden crust. As a quiche has a nice isolating crust, the extreme measures needed for other quiches like a water bath shouldn't be necessary.